The present invention relates generally to text input devices for microprocessor-based electronic equipment, and more particularly to a multiple character text input device having a limited number of input keys.
Many types of electronic equipment such as hand held computers, TVs, VCRs, cable TV and satellite TV set-top boxes, PCs, cordless telephones, and cellular telephones are configured to accept and even require information such as alphanumeric text, numbers, and assorted symbols to be provided by a user. For instance, many types of electronic equipment are configured with electronic mail. Electronic mail which is quickly becoming ubiquitous in both the business and home environments requires the input of at least 26 characters of the alphabet, numbers, and assorted symbols when using the English language.
Text information, letters, numbers, and symbols, is usually provided to the many types of electronic equipment by text input devices built in the electronic equipment such as keyboards built in a hand held computer or keypads on a cellular telephone. Another conventional way of providing text information to the many types of electronic equipment is through separate hand held text input devices such as a remote control or an infrared keyboard for a VCR, TV, cable TV set-top box, satellite TV set-top box, or PC. With input devices built in the many types of electronic equipment and hand held text input devices being continuously reduced for convenience and portability, the area on the input devices for inputting text information is also being Internet services, electronic TV program guides, and other types of applications requiring the input of alphanumeric text and with input devices having a limited area for providing the alphanumeric text input, reconciliation of these competing forces has become a difficult problem.
Conventionally, the primary interface for providing information to the many types of electronic equipment is a keyboard. For instance, in the home environment TV-based computers such as WebTV are configured with Internet services such as electronic mail and browsers which require alphanumeric text input and an infrared keyboard which provides the text input to the TV-based computer. However, like most conventional keyboards, the infrared keyboard is bulky and cumbersome and presents yet another remote control to a user who already has too many remote controls in their living room. Additionally, these keyboards are not ideal for use with electronic devices that are quite compact, such as cellular phones. Although keyboards can be reduced in size as in the case of hand held computers, eventually a point is reached where the keyboard cannot be reduced without making the keyboard difficult and inefficient to use. Accordingly, the next input interface of choice for many types of electronic equipment is a keypad.
Conventionally, keypads have a limited number of keys, usually 12, and require a sequential input scheme for providing alphanumeric text to the electronic equipment. For example, to enter the letter "C", a user presses a number 2 key on the keypad three times to select the letter "C" out of the letters A, B and C associated with the number 2 key of the keypad. Hashimoto (U.S. Pat. No. 4,918,721) discloses such an input scheme. However, the input scheme is complicated and requires some memorization by a user. Therefore, using such an input device is operationally confusing to a user and difficult to learn.
Other devices such as one disclosed by Lin et al. (U.S. Pat. No. 5,528,235) have a multi-function data processing key having a key top divided into multiple surfaces indicating different letters of the alphabet. Also, Ojima (U.S. Pat. No. 4,029,915) describes a calculator keyboard having a row of keys each adapted to be tilted in one of four directions, and Hsieh (U.S. Pat. No. 4,896,003) describes a multi-directional switch using a ball bearing and deformable supports. Each of these devices is mechanically complicated and thereby costly to manufacture. Additionally, these devices are confusing to operate. Accordingly, methods and devices for providing alphanumeric text input that are simpler in construction and in operation are desirable.
Furthermore, with TV and cable TV channels becoming more numerous, exceeding more than 100 channels on some cable networks, program selection is becoming more confusing. New types of electronic equipment attempt to address this problem by providing on-screen program information. While viewing the on-screen information, a user selects a TV program from a category, such categories are grouped by program type like sports. However, partly due to the lack of a suitable text input device, categorizing and searching for specific subjects or text strings included in the program information is difficult. With a suitable text input device, a user can search for an actress or actor's name, a movie title, or a keyword in the description of a program. Accordingly, methods and devices providing text input for electronic equipment which traditionally did not require text input are also desirable.